/* Copyright  2009
   @Author
   Richard Changde Yin            e-mail yinchangde@hotmail.com

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
/**
 *
 * @filename: xid.cc
 */
#include <global.h>

// std
#include <string.h>

#include <db_pthread.h>
#include <hash.h>
#include <xid.h>

#include <mutex.h>

XID::XID()
{}

bool XID::eq(XID *xid)
{
  return eq(xid->gtrid_length, xid->bqual_length, xid->data);
}

bool XID::eq(long g, long b, const char *d)
{
  return g == gtrid_length && b == bqual_length &&!memcmp(d, data, g+b);
}

void XID::set(XID *xid)
{
  memcpy(this, xid, xid->length());
}

void XID::set(long f, const char *g, long gl, const char *b, long bl)
{
  formatID= f;
  memcpy(data   , g,    gtrid_length= gl);
  memcpy(data+gl, b,    bqual_length= bl);
}

void XID::set(uint64_t xid)
{
  my_xid tmp;
  formatID= 1;
  set(COLLAPSAR_XID_PREFIX_LEN, 0, COLLAPSAR_XID_PREFIX);
  ::memcpy(data + COLLAPSAR_XID_PREFIX_LEN, &server_id, sizeof(server_id));
  tmp= xid;
  ::memcpy(data + COLLAPSAR_XID_OFFSET, &tmp, sizeof(tmp));
  gtrid_length= COLLAPSAR_XID_GTRID_LEN;
}

void XID::set(long g, long b, const char *d)
{
  formatID= 1;
  gtrid_length= g;
  bqual_length= b;
  memcpy(data, d, g+b);
}

bool XID::is_null()
{
  return formatID == -1;
}

void XID::null()
{
  formatID= -1;
}

my_xid XID::quick_get_my_xid()
{
  my_xid tmp;
  memcpy(&tmp, data+COLLAPSAR_XID_OFFSET, sizeof(tmp));
  return tmp;
}

my_xid XID::get_my_xid()
{
  return gtrid_length == COLLAPSAR_XID_GTRID_LEN && bqual_length == 0 &&
    !memcmp(data+COLLAPSAR_XID_PREFIX_LEN, &server_id, sizeof(server_id)) &&
    !memcmp(data,COLLAPSAR_XID_PREFIX,COLLAPSAR_XID_PREFIX_LEN) ?
    quick_get_my_xid() : 0;
}

uint32_t XID::length()
{
  return sizeof(formatID)+sizeof(gtrid_length)+sizeof(bqual_length)+
                gtrid_length+bqual_length;
}

unsigned char *XID::key()
{
  return (unsigned char *)&gtrid_length;
}

uint32_t XID::key_length()
{
  return sizeof(gtrid_length)+sizeof(bqual_length)+gtrid_length+bqual_length;
}

/***************************************************************************
  Handling of XA id cacheing
***************************************************************************/
pthread_mutex_t LOCK_xid_cache;
HASH xid_cache;

extern "C" unsigned char *xid_get_hash_key(const unsigned char *, size_t *, bool);
extern "C" void xid_free_hash(void *);

unsigned char *xid_get_hash_key(const unsigned char *ptr, size_t *length,
                        bool )
{
  *length=((XID_STATE*)ptr)->xid.key_length();
  return ((XID_STATE*)ptr)->xid.key();
}

void xid_free_hash(void *ptr)
{
  if (!((XID_STATE*)ptr)->in_session)
    free((unsigned char*)ptr);
}

bool xid_cache_init()
{
  pthread_mutex_init(&LOCK_xid_cache, MY_MUTEX_INIT_FAST);
  return hash_init(&xid_cache, &my_charset_bin, 100, 0, 0,
                   xid_get_hash_key, xid_free_hash, 0) != 0;
}

void xid_cache_free()
{
  if (hash_inited(&xid_cache))
  {
    hash_free(&xid_cache);
    pthread_mutex_destroy(&LOCK_xid_cache);
  }
}

XID_STATE *xid_cache_search(XID *xid)
{
  SimpleMutex xidmutex(LOCK_xid_cache);
  XID_STATE *res=(XID_STATE *)hash_search(&xid_cache, xid->key(),
                                         xid->key_length());

  return res;
}

bool xid_cache_insert(XID *xid, enum xa_states xa_state)
{
  XID_STATE *xs;
  bool res;
  SimpleMutex xidmutex(LOCK_xid_cache);

  if (hash_search(&xid_cache, xid->key(), xid->key_length()))
    res=0;
  else if (!(xs=(XID_STATE *)malloc(sizeof(*xs))))
    res=1;
  else
  {
    xs->xa_state=xa_state;
    xs->xid.set(xid);
    xs->in_session=0;
    res=hash_insert(&xid_cache, (unsigned char*)xs);
  }

  return res;
}

bool xid_cache_insert(XID_STATE *xid_state)
{
  SimpleMutex xidmutex(LOCK_xid_cache);

  assert(hash_search(&xid_cache, xid_state->xid.key(),
                          xid_state->xid.key_length())==0);
  bool res=hash_insert(&xid_cache, (unsigned char*)xid_state);

  return res;
}

void xid_cache_delete(XID_STATE *xid_state)
{
  SimpleMutex xidmutex(LOCK_xid_cache);

  hash_delete(&xid_cache, (unsigned char *)xid_state);

}
